Combined adjustable square and protractor



Jan. 18, 1955 D. c. EVANS 2,699,609

COMBINED ADJUSTABLE SQUARE AND PROTRACTOR Filed 001;. 24, 1952 INVENTOROwl/IQ 0. Ema/w;

z m pm flmzdam ATTORNEM United States Patent COMBINED ADJUSTABLE SQUAREAND PROTRACTOR David C. Evans, Prince Rupert, British Columbia, CanadaApplication October 24, 1952, Serial No. 316,747 3 Claims. (CI. 3397)This invention relates to carpenters adjustable squares and moreparticularly to an adjustable square having a protractor blade mountedthereon and extending along one of the straight edges thereof.

It is among the objects of the invention to provide an improvedcombination square and protractor in which the square hasperpendicularly disposed edges and a protractor blade is pivotallyconnected to the square and extends along one of the perpendicularlydisposed edges thereof; in which the square is recessed along the edgethereof adjacent the protractor blade to receive the latter fully intothe corresponding portion of the square; in which the protractor bladeis adjustable in length and may be swung to various angular positionsrelative to the blade of the square and a scale is provided on the bladeof the square with which the protractor blade cooperates to indicate theangularity between the protractor blade and the blade of the square; andwhich is simple and durable in construction, economical to manufacture,effective in use, and neat and attractive in appearance.

Other objects and advantages will become apparent from a considerationof the following description and the appended claims in conjunction withthe accompanying drawing wherein:

Figure 1 is a side elevational view of a combined adjustable square andprotractor illustrative of the invention;

Figure 2 is a bottom plan view of the square and protractor combinationillustrated in Figure 1;

Figure 3 is a cross sectional view on an enlarged scale on the line 33of Figure 2;

Figure 4 is a fragmentary cross sectional view on a further enlargedscale on the line 4-4 of Figure 3;

Figure 5 is a cross sectional view on an enlarged scale on the line 5-5of Figure 3;

Figure 6 is a cross sectional view on an enlarged scale on the line 66of Figure 1;

Figure 7 is a fragmentary side elevational view of a somewhat modifiedform of the device of the invention; and

Figure 8 is a cross sectional view on an enlarged scale on the line 8--8of Figure 7.

With continued reference to the drawing, the car penters square asillustrated, is of known construction and includes a blade, generallyindicated at 10, and a head, generally indicated at 11, secured to theblade and slidable therealong to various selected positions ofadjustment longitudinally of the blade.

The blade 10 of the square is a thin, rectangular bar of suitablematerial, such as steel, having straight and substantially parallel sideedges with scales of longitudinal measurements, as indicated at 12,disposed on the faces and extending along the edges thereof and having agroove 13 extending longitudinally thereof and medially of one of itsfaces.

The head 11 is a body of suitable material, such as steel or aluminum,having portions materially thicker than the thickness of the blade 10and having at one end a notch or slot which slidably receives the bladeand is of a depth substantially equal to one half the width of theblade. A screw receiving tubular formation 14 is provided in the headextending to the end of the head in which the blade receiving notch isprovided and a thumbscrew 15 extends through this formation 14 and hason one end a dog formation engaging in the groove 13 of the blade tolock the head to the blade when the thumbscrew 15 is tightened. Theblade has one working edge 16 disposed at an angle of approximately 45degrees to the side edges of the blade 10 and has a second working edge17 disposed at an angle of degrees to the side edges of the blade. Theedges 16 and 17 have a width materially greater than the thickness ofthe blade 10 and, in the normal use of the square, are adapted to restagainst a side or end surface of a work piece, such as a piece oflumber, while the blade 10 rests upon the upper surface of the workpiece and is positioned relative to the work piece for scribing a linethereon for a saw cut or similar operation.

In the device of the present invention, the head 11 is provided alongthe edge 17 thereof with a longitudinally extending slot or groove 18.The slot or groove 18 extends substantially along the rnid-widthlocation of the edge portion 17 of the head of the square and from oneend to the other of the arm 19 of the head on which the working edge 17is provided.

A protractor blade, generally indicated at 20, has one end received inthe groove 18 at the end of the arm 19 remote from the square blade 10and a pivot bolt 21 extends through registering apertures in theprotractor blade and in the material of the head at the opposite side ofthe groove 18 and is provided on one end with a looking nut 22 by meansof which the protractor blade can be releasably secured in variousselected positions of angularity relative to the Working edge 17 of thehead 11 of the square.

The protractor blade 20 is an adjustable length blade and comprises twobars 23 and 24 of elongated, rectangular shape disposed in overlappingrelationship and in longitudinal alignment with each other.

In the form of the invention illustrated in Figures 1 to 6 inclusive,the bar 23 is pivotally secured at one end to the head 11 by the pivotscrew 21 and the bar 24 is provided with a closed slot 25 extendingmedially of the width thereof from a location near one end to a locationnear the other end of this bar.

A pair of pins 26 and 27 are secured in the bar 22 at locations spacedalong the mid-width location of this bar and adjacent the end thereofremote from the pivot screw 21 and these pins extend through the slot 25in the bar 24 to secure the bar 24 to the bar 23 for longitudinalsliding movement of the former relative to the latter. The edges of theslot 25 are beveled and the pins 26 and 27 have inwardly beveled headsreceived in the slot 25, as is particularly illustrated in Figure 6, topro vide frictional resistance to movement of the bar 24 longitudinallyof the bar 23, so that the bars 23 and 24 will remain in selectedpositions of longitudinal adjustment relative to each other.

The protractor blade 20, when fully contracted in length, has a lengthsubstantially equal to the distance from the pivot screw 21 to theadjacent edge of the blade 10 and has a width substantially equal to thedepth of the groove or recess 18, so that the blade will fit completelyinto the recess, when not in use, and will not extend beyond the surfaceof the working edge 17 of the head of the square.

When the protractor blade is expanded to its maximum length, it has alength greater than the distance from the pivot screw 21 to the edge ofthe blade 10 remote from the pivot screw and the bar 24 of theprotractor blade is then disposed against one side of the blade 10 ofthe square, as is particularly illustrated in Figure 1.

An arcuate scale 28 is provided on the side of the blade 10 againstwhich the bar 24 of the protractor blade bears, and this scale iscentered on the axis of the pivot screw 21 and is divided by suitablescale marks into sections which indicate the angular relationshipbetween the protractor blade 20 and the working edge 17 of the head ofthe square which working edge is disposed perpendicular to the sideedges of the blade.

With this arrangement, the protractor blade can be withdrawn from thegroove 18, extended in length, and then positioned along the scale 28,so that it is at a desired angle to the edge 17 of the head of thesquare and the nut 22 of the pivot screw may then be tightened to lockthe protractor blade in the selected position of angularity relative tothe working edge 17 of the head and the side edges of the blade of thesquare. The

square may now beusedfor certainnoperatiions,v such. as

framing rafters for a building or for marking framings for cuts atangles other than 90 or 45 degrees.

As is particularly shown inFigure 5., the:- material.

of the head 11 is provided at one side of, the. groove. 18 with a tappedhole 29 disposed adjacent the squareblade and aset screw 30 having awinghead or thumb-- the; pivot pin 21, includes; a cylindrical shankhaving screw threaded formations, disposed one at each end thereof andthat in addition to the nut 22 threadedon one end of this shankand.having. a; lever or handle projecting radially therefrom, a head, 32 isthreaded onto the other end of the shank andhas a, cylindrical peripheryreceived in an aperture provided in the head of the square at. thecorresponding-side of. the groove 18 and..bearing against the; adjacent.side of the-bar 23 of: the protractor: blade. A, formation 33on theouter end of the head32 provides a, transversely extending screwdriverslot 34 for tightening the head. onto the shank of the screw and athrust washer 35 is disposed between the nut 22. and the adjacentsurface-of the head of the square, so. that, when the nut is tightenedonto the pivot bolt the. end portion of the bar 23 receiving the pivotbolt is firmly clamped betweenthe head 32 and. the portion ofthe. headofthe square. adjacent the nut 22 to lock the :protractor blade in:selected positions of angular adjustment relative to the head of'ithesquare.

In the modified form of the arrangement illustrated in Figures 7 and 8,the construction is. the same as that illustrated in Figures 1. to 6inclusive, and described above, except that the bar 24' of theprotractor blade 20, instead of being provided Witha longitudinallyextending slot, is provided in oneside thereof with a longitudinallyextending, undercut groove 36, and the bar 23, instead of being providedwith spaced apart pins, is provided with a longitudinally extending key-37 of dovetailed cross sectional shape slidably received in the groove36 in the bar 24. The key 37 and groove 36- interconnectthe bars 23 and24' for sliding movements longitudinally of each other and a set screw38 is threaded intoa tapped hole in the bar 24 near the end of this baradjacent the pivot screw 21 and engages atits inner end the outersurface of the key or spline 36 toreleasablylock the two bars intoselected positions of longitudinal adjustment relative to each other.

The invention may be embodied in other specific forms without departingfrom the spirit or essential characteristics thereof. The presentembodiments-are, therefore, to be considered in all respects asillustrative andnot restrictive', the scope of the invention beingindicated by the appended claims rather than by the foregoingdescription, and all changes which come within the mean? ing and rangeof equivalency of the claims are, therefore, intended to be embracedtherein.

What is claimed is:

l. A combined adjustable square and protractorcomprising a square blade,a head. connected to said' blade and movable therealong to selectedpositions of adjustment longitudinally thereof, said head havingaworking edge perpendicular to said square blade and having agroove'extending medially along said working edge, an

adjustableslength protractor. bladepivotally connected at one end tosaid head at the end of said working edge remote from said square bladeand completely receivable in the groove in said head when fullycontracted in length, said protractor blade overlying said one side ofsaid square blade when fully expanded in length, and an arcuate scale onsaid square blade cooperating with said protractor blade to indicate theangularity of the latter to said'work'ing edge-of the head.

2. A combined adjustable square and protractor com prisinga-squareblad'e, a head, connected to saidv blade and movable therealongto selected positions of adjustment, longitudinally; thereof, saidheadhavinga working edge perpendicular to said square blade and having agroove extending medially along'said working edge, an adjustable lengthprotractor blade pivotally connected at one end to said head at the endof said Working edge remote. from said square blade. and completelyreceivablein the groove. in said head when fully contractedfin length,said protractor blade overlying said one side of.

saidsqu'are blade when fully expanded in length, and an arcuate scaleonsaid square blade'cooperating with: said protractor bladetoindicatethe angularity of the latter:

to said working edge of the head, said'protractor blade comprisingtwo.bars-of'elongated rectangular shape disposed'inlongitudinalalignment andoverlapping relationship, One of said bars having av closed slotextendinglongitudinally thereof and provided with beveled edges, andpins securedin the other of said bars at spaced apart locationstherealong and having beveled heads received.

in said. slot.

3. A. combined. adjustable square and protractor com: prising a. squareblade, ahead connected to. said blade and movable therealong to selectedpositions of adjustment longitudinally thereof, said head-having aW01king edge perpendicular to said square blade and having a grooveextending medially along said working edge an adjustable lengthprotractor blade pivotally connected atone end to'said head atthe end ofsaid working edge remote from saidsquare blade and completely receivablein the groove in said head when fullycontracted in length, saidprotractor blade overlying said one side of said square blade when fullyexpanded in length, and an arcuate scale on said square bladecooperating with said protractor blade to. indicate the angularity ofthe latter to said working" edge of the head, said protractor bladecomprising; two bars of elongated rectangular shape disposed inlongitudinal alignmentand overlapping relationship, one of said barshavinga closed slot extending longitudinally thereof and provided withbeveled edges, andpins secured inthe other of said bars at spaced apartlocations therealong and having beveled heads received in said slot, anda set screw threaded into a tapped hole in said head at one side ofsaidgroove and;

engageable with said protractor blade whenthe latter is in said. grooveto releasably' lock said protractor blade inv the groove in said head.

References Cited in thefile of thispatent

